August 27, 2012 4:56am EDTAugust 27, 2012 1:09am EDTThe New York Jets' offense again failed to find the end zone in a preseason game, this time against the Carolina Panthers. There has to be cause for concern despite what Mark Sanchez and company are saying.

In fact, they look to be in trouble already. Starting tight end Dustin Keller suffered a hamstring injury Sunday, and the severity of his injury was not immediately known. Backup tight end Josh Baker suffered a potentially serious knee injury in the second quarter. Linebacker David Harris (ankle) also left the game with an injury.

The wide receiving corps was already banged up. Santonio Holmes (one catch, eight yards) made his preseason debut Sunday night, but he has been nursing a rib injury. Jeremy Kerley and Chaz Schilens also have injuries.

If the Jets are going to establish an offensive identity, it will have to happen during the regular season. Right now, we don’t know what the Jets are offensively, but what they have shown has not been very good.

Mark Sanchez (11-for-18, 123 yards) threw the ball well against the Panthers, but his receivers did not always catch it. Rookie wide receiver Stephen Hill had several drops, including a ball that slipped through his hands right into the arms of Carolina's Captain Munnerlyn for an interception.

Then there was Tim Tebow (4-for-14, 55 yards, five rushes for 45 yards). Tebow still looks much better as a runner than as a thrower. When Tebow throws it, you can never be sure exactly where it’s going.

He threw a bad interception on a pass over the middle, and another of Tebow’s passes should have been intercepted, but it was dropped. One of Tebow’s passes Sunday night was so wickedly off target, it sailed way out of bounds and slammed into a Jets banner against a sideline wall.

"He threw it so hard, I was glad it never hit a cheerleader," coach Rex Ryan joked afterward.

Ryan can joke now. It will not be a joke if the Jets’ offense does not get better quickly. We know they are saving plenty of stuff for the regular season. We have not seen their Wildcat package featuring Tebow. We surely have not seen much of their passing offense.

But there is no guarantee it will work when they unveil it. The challenge of starting Sanchez, working in Tebow and keeping the offense in a successful rhythm will be a delicate balance. If it does not work, the Jets will be in serious danger of imploding. They were a disappointing 8-8 last season, and they had locker room issues. If the defense holds up its end, but the offense does not, the Jets could fracture again.

Jets linebacker Bart Scott said he did not believe the Jets’ defense would turn on the offense.

"You pick each other up," Scott. "You hope both are playing lights out."

But right now, the Jets’ defense looks far better than the offense. Neither Sanchez nor Tim Tebow will play in the preseason finale against the Eagles, so the Jets’ first-team offense will have to iron out its problems in practice to get ready for Buffalo.

The Jets are asking their fans not to be frustrated by what they have seen so far in the preseason. That is very difficult. At Sunday’s game, you could sense fans growing restless. Tebow was cheered when he entered the game in the third quarter, but there were groans after some of his off-target passes.

Tebow is popular, but so is winning. If the Jets do not win, this season will not be much fun for anyone in their locker room. Ryan had a very successful first two seasons with the Jets, reaching the AFC championship game for two consecutive years. But the Jets came crashing back down to earth last season.

Ryan believes that last season was an aberration. But it could have been the start of a franchise in decline. And the AFC East looks tougher. The Patriots are the Patriots. The Bills have improved during the offseason. Even the Dolphins have hope for the future in the person of rookie quarterback Ryan Tannehill. If this season goes badly for the Jets, both Ryan and general manager Mike Tannenbaum will have plenty of explaining to do.

Right now, the Jets can tell you that the preseason does not count. They are right. But the Jets’ performance in the preseason is not convincing anyone that they are a Super Bowl contender.